Mohamed Aboelfotouh
Air that cannot leave the cavity during the shot ends up as porosity in the casting. Flat vents at the parting line are simple, but they must be very shallow to stop the metal, so their area is small and they block quickly. A chill vent solves this with a ....
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Mohamed Aboelfotouh
Some areas of a die-casting die cannot be reached by normal cooling channels: slender core pins, thin cores between ribs, bosses deep inside the casting. These areas run hottest in the die, and they cause shrinkage porosity in the casting next to them, so ....
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Mohamed Aboelfotouh
A die casting die for aluminum is a large investment, and its life is counted in shots. Some dies need major repair after 50,000 shots while others making similar parts pass 200,000. The difference is rarely luck. It comes from steel quality, heat treatme ....
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Mohamed Aboelfotouh
A casting put on a machine that is too small flashes, wears the die and gives porous parts. A machine that is too large costs more per hour and often fills the shot sleeve so poorly that air is mixed into every shot. Matching the casting to the machine ta ....
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Mohamed Aboelfotouh
Before every shot, the cavity, the runner and the empty part of the shot sleeve are full of air. The metal fills the cavity in a few hundredths of a second, so that air has very little time to leave. What does not leave ends up inside the casting as gas p ....
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Mohamed Aboelfotouh
Porosity is the most common reason die castings are rejected for leaks, weak sections or holes opened by machining. There are two different kinds, with different causes and opposite fixes. Adding pressure will not remove trapped air, and better venting wi ....
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Mohamed Aboelfotouh
The gate is the smallest section in the whole feeding system of a die casting die, and it controls two things at once: how long the cavity takes to fill and how fast the metal enters it. If the gate is too small, the machine cannot deliver the flow and th ....
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Mohamed Aboelfotouh
High-pressure die-casting (HPDC) is similar to permanent mold casting except that the metal is injected into the mold under a high pressure of 10-210MPa. This results in a more uniform part with a generally good surface finish and good dimensional ....
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